Electrical wiring device

• US 7,619,860 B1
• Filed: 09/01/2006
• Issued: 11/17/2009
• Est. Priority Date: 11/21/2000
• Status: Expired due to Term

• Current Assignee: Pass And Seymour Incorporated (Legrand SA)
• Original Assignee: Pass And Seymour Incorporated (Legrand SA)
• Inventors: Packard, Thomas N., Finlay, David A. Sr.
• Primary Examiner(s): Jackson; Stephen W
• Assistant Examiner(s): WILLOUGHBY, TERRENCE RONIQUE
• Application Number:
  US11/469,596
• Time in Patent Office: 1,173 Days
• Field of Search: 361 42- 50
• US Class Current: 361/42
• CPC Class Codes: H02H 3/338 also responsive to wiring error, e.g. loss of neutral, break

Abstract

The present invention is directed to a protective device that includes a hot line terminal, a neutral line terminal, a hot load terminal, and a neutral load terminal. A low pass filter circuit has a capacitor coupled in series with a solenoid coil of the protective device. The low pass filter is coupled across the hot line terminal and the neutral line terminal. A miswire detection circuit is configured to detect a miswire fault condition when AC power is coupled to the hot load terminal and the neutral load terminal. An interrupting contact assembly includes interrupting contacts that provide electrical continuity between the hot line terminal and the hot load terminal and the neutral line terminal and the neutral load terminal in a reset state. The interrupting contacts are open in a tripped state. An indicator circuit is coupled to the interrupting contact assembly and being configured to indicate the tripped state and/or the reset state.

Claims

1. A protective device for use in an AC electrical distribution system, the device comprising:

a hot line terminal, a neutral line terminal, a hot load terminal, and a neutral load terminal, the hot line terminal and the neutral line terminal being configured to be coupled to the AC electrical distribution system;

a low pass filter circuit having a capacitor coupled in series with a solenoid coil of the protective device, the low pass filter being coupled across the hot line terminal and the neutral line terminal and configured to filter transient over-voltage signals propagating in the AC electrical distribution system;

a miswire detection circuit configured to detect a miswire fault condition when AC power is coupled to the hot load terminal and the neutral load terminal;

an interrupting contact assembly including interrupting contacts that provide electrical continuity between the hot line terminal and the hot load terminal and the neutral line terminal and the neutral load terminal in a reset state, the interrupting contacts being open in a tripped state; and

an indicator circuit coupled to the interrupting contact assembly and being configured to indicate the tripped state and/or the reset state.

2. The protective circuit of claim 1, further comprising a surge protection device coupled in parallel with the low pass filter, the surge protection device being configured to clamp transient voltages above a predetermined threshold level.

3. The protective circuit of claim 1, wherein the miswire detection circuit is configured to open circuit a predetermined period of time after AC power is coupled to the hot line terminal and neutral line terminal.

4. The protective circuit of claim 1, wherein the miswire detection circuit includes at least one fusible element configured to open-circuit a predetermined period of time after the AC power is coupled to the hot line terminal and neutral line terminal.

5. The protective circuit of claim 1, further comprising a fault detection circuit coupled to the miswire detection circuit and the low pass filter, the fault detection circuit being configured to generate a fault detection signal in response to detecting at least one fault condition, the at least one fault condition including the miswire fault condition.

6. The protective circuit of claim 5, wherein the fault detection circuit is configured to detect a ground fault condition.

7. The protective circuit of claim 5, wherein the fault detection circuit is configured to detect a grounded neutral condition.

8. The protective circuit of claim 5, wherein the fault detection circuit is configured to detect an arc fault condition.

9. The protective circuit of claim 5, further comprising a rectifier element coupled to the fault detection circuit, the rectifier element being turned ON in response to the fault detection signal, the solenoid coil of the low pass filter being coupled between the rectifier element and the interrupting contacts and configured to trip the interrupting contacts when the rectifier is in the ON state.

10. The protective circuit of claim 1, wherein the interrupting contacts include four sets of interrupting contacts.

11. The protective circuit of claim 1, wherein the indicator element is configured to indicate a trip condition, a miswire condition, and/or an end-of-life condition.

12. A protective device for use in an AC electrical distribution system, the device comprising:

a hot line terminal, a neutral line terminal, a hot load terminal, and a neutral load terminal, the hot line terminal and the neutral line terminal being configured to be coupled to the AC electrical distribution system;

a low pass filter circuit having a capacitor coupled in series with a solenoid coil of the protective device, the low pass filter being coupled across the hot line terminal and the neutral line terminal and configured to filter transient over-voltage signals propagating in the AC electrical distribution system;

a miswire detection circuit configured to detect a miswire fault condition when AC power is coupled to the hot load terminal and the neutral load terminal; and

an interrupting contact assembly including four sets of interrupting contacts configured to provide electrical continuity at least between the hot line terminal and the hot load terminal and the neutral line terminal and the neutral load terminal in a reset state, the four sets of interrupting contacts being open in a tripped state.

13. The protective circuit of claim 12, further comprising a surge protection device coupled in parallel with the low pass filter, the surge protection device being configured to clamp transient voltages above a predetermined threshold level.

14. The protective device of claim 13, wherein the surge protection device includes a MOV.

15. The protective circuit of claim 12, wherein the miswire detection circuit is configured to open circuit a predetermined period of time after AC power is coupled to the hot line terminal and neutral line terminal.

16. The protective circuit of claim 12, wherein the miswire detection circuit includes at least one fusible element configured to open-circuit a predetermined period of time after the AC power is coupled to the hot line terminal and neutral line terminal.

17. The protective circuit of claim 12, further comprising a fault detection circuit coupled to the miswire detection circuit, the fault detection circuit being configured to generate a fault detection signal in response to detecting at least one fault condition.

18. The protective circuit of claim 17, wherein the at least one fault condition includes the miswire fault condition.

19. The protective circuit of claim 17, wherein the four sets of interrupting contacts are configured to open in response to receiving the fault detection signal.

20. The protective circuit of claim 17, wherein the fault detection circuit is configured to detect a ground fault condition.

21. The protective circuit of claim 17, wherein the fault detection circuit is configured to detect a grounded neutral condition.

22. The protective circuit of claim 17, wherein the fault detection circuit is configured to detect an arc fault condition.

23. The protective circuit of claim 17, further comprising a rectifier element coupled to the fault detection circuit, the rectifier element being turned ON in response to the fault detection signal, the solenoid coil of the low pass filter being coupled between the rectifier element and the interrupting contacts and configured to trip the interrupting contacts when the rectifier is in the ON state.

24. The protective circuit of claim 23, further comprising an indicator circuit coupled to the rectifier element, the indicator circuit being energized when the rectifier is short circuited to thereby indicate an end-of-life condition.

25. The protective circuit of claim 12, further comprising an indicator circuit coupled to the interrupting contact assembly, the indicator circuit is configured to indicate a trip condition, a miswire condition, and/or an end-of-life condition.

26. A protective device for use in an AC electrical distribution system, the device comprising:

a hot line terminal, a neutral line terminal, a hot load terminal, and a neutral load terminal, the hot line terminal and the neutral line terminal being configured to be coupled to the AC electrical distribution system;

a low pass filter circuit having a capacitor coupled in series with a solenoid coil of the protective device, the low pass filter being coupled across the hot line terminal and the neutral line terminal and configured to filter transient over-voltage signals propagating in the AC electrical distribution system;

a surge protection device coupled in parallel with the low pass filter, the surge protection device being configured to clamp transient voltages above a predetermined threshold level;

a miswire detection circuit configured to detect a miswire fault condition when AC power is coupled to the hot load terminal and the neutral load terminal; and

an interrupting contact assembly including four sets of interrupting contacts configured to provide electrical continuity between at least the hot line terminal and the hot load terminal and the neutral line terminal and the neutral load terminal in a reset state, the four sets of interrupting contacts being open in a tripped state.

27. The protective device of claim 26, wherein the surge protection device is a MOV.

28. The protective device of claim 26, wherein the miswire detection circuit is configured to open circuit a predetermined period of time after AC power is coupled to the hot line terminal and neutral line terminal.

29. The protective device of claim 26, wherein the miswire detection circuit includes at least one fusible element configured to open-circuit a predetermined period of time after the AC power is coupled to the hot line terminal and neutral line terminal.

30. The protective device of claim 26, further comprising a fault detection circuit coupled to the miswire detection circuit, the fault detection circuit being configured to generate a fault detection signal in response to detecting at least one fault condition.

31. The protective device of claim 30, wherein the at least one fault condition includes the miswire fault condition.

32. The protective device of claim 26, wherein the miswire detection circuit generates a miswire detection signal that does not generate the at least one fault condition.

33. The protective device of claim 26, further comprising an indicator circuit coupled to the interrupting contact assembly, the indicator circuit is configured to indicate a trip condition, a miswire condition, and/or an end-of-life condition.